Policy-based cryptography and applications

FC 2005, 9th International Conference on Financial Cryptography and Data Security, 28 February-03 March 2005, Roseau, The Commonwealth of Dominica / Also published in LNCS Volume 3570

In this paper, we formulate the concept of policy-based cryptography which makes it possible to perform policy enforcement in large-scale open environments like the Internet, with respect to the data minimization principle according to which only strictly necessary information should be collected for a given purpose. We use existing cryptographic primitives based on bilinear pairings over elliptic curves to develop concrete policy-based encryption and signature schemes which allow performing relatively efficient encryption and signature operations, with respect to policies formalized as monotonic logical formulae. we illustrate the properties of our policy-based cryptographic schemes through the description of three application scenarios.